Hornbill eating, preening, regurgitating and losing balance

“It was early morning on Labour Day (1st May 2010). An Oriental Pied Hornbill (Anthracoceros albirostris) was observed to be harvesting fruits from one of the many MacArthur Palm trees (Ptychosperma macarthurii), which were fruiting in the area.

“It selected only the ripened red-coloured fruits; using the tip of its beak to pick them up. The selected fruits were then flicked expertly into its oral cavity – always one at a time (above). When it had its fill, it flew to a nearby tree and began to preen itself. After some preening, it suddenly flipped its head to one side to an angle of about ninety degrees. In just an instance, its head resumed to its normal position. Its mandibles were seen opening narrowly and then closing. Its head was then tilted up slightly with its beak partially opened. A slight movement of its head forward resulted in one seed emerging from out of nowhere to appear briefly at the tip of its beak (below). The seed that was regurgitated was then allowed to drop into the bushes below.

“Subsequently, this hornbill continued to feed on the MacArthur Palm for another two rounds, preening itself in different trees in between. There was no other regurgitation seen.

“What happened next was totally unexpected. The hornbill somehow lost its balance and had to perform some acrobatics to salvage itself from the indignity of being upside-down (above). It found itself in an upside-down position when it suddenly plunged forward with its head and long neck going well below the level of its perch. Its strong grip on the perch prevented it from falling off the branch. It managed to balance itself by half-spreading its wings. Somehow, it gathered sufficient strength to lift itself awkwardly back to its normal upright perching posture.

“Birds do not normally lose their balance on their perches. This is the first time that I have caught sight of a bird losing its balance while it was perching.”

Kwong Wai Chong
Singapore
10th May 2010

4 Responses

  1. I think this is a Senior Oriental Pied Hornbill?

  2. Interesting! You mean it’s old and had fallen? It could be junior too – may be trying out some slick move.
    Seriously, is there any way to tell its age?

  3. Richard Corlett

    This “ballistic feeding” mechanism – throwing the fruit from the beak tip directly into the throat – is used by both hornbills and the unrelated toucans, and completely by-passes the tongue. Presumably the birds do not taste the fruit at all until after it is swallowed.

  4. You really saved my skin with this ifnromatoin. Thanks!

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